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The Sleepless Sentinel

No more Sundarbans
Crocodiles search for new habitat!

Staff reporter, Nature India News Bureau, Sundarbans: According to several local sources, the Indian Sundarbans will perhaps lose its Crocodile population from the estuaries. The Estuarine Crocodile, Crocodylus porosus are basically from the northern part of Australia and the eastern coast of India and parts of Southeast Asia. Apart from the eastern coast of India, this crocodile is extremely rare in the Indian subcontinent. A huge population of saltwater crocodiles (consisting of many large adults, including a 7 meter male) has been reported from the Bhitarkanika Wildlife Sanctuary of Orissa. Once, these crocodiles were known to exist in smaller number through out the Indian and Bangladesh portions of the Sundarbans, but due to various anthropological, geological factors coupled with continuous habitat loss and human interferences they are fast disappearing.

Though critical, a stable population is still present in the Irrawaddy Delta of Myanmar. The population is irregular in Indonesia and Malaysia with some areas having large population (Borneo, for example) and others with very small, at-risk populations (e.g. the Philippines). A very small, invasive and soon to be extinct population is present at Vanuatu (where the population officially stands at only three) and a decent but at-risk population at Palau. These crocodiles normally travel long distances in sea because of which, individual saltwater crocodiles are occasionally found at locales where they are not native. Such long traveling individuals have historically been reported in New Caledonia, Iwo Jima, Fiji, and even in the relatively frigid Sea of Japan (thousands of miles from their native territory)! They have even been reported to migrate from their native zone to far-off estuaries during the warmer and wet season. The presence of saltwater crocodile within the river system of Fraser Island is evidence to the fact, as these species were not native to the rivers of Fraser Island.

The specie generally spends the tropical wet season in freshwater swamps and rivers. They move downstream to estuaries in the dry season, and sometimes travel far out in the sea. Crocodiles compete fiercely with each other for territory. Dominant males occupy the most suitable stretches of freshwater creeks and streams. Junior crocodiles are thus forced into the more marginal river systems and sometimes into the ocean. This explains the large distribution of the animal (ranging from the east coast of India to northern Australia) as well as its being found in odd places on occasions (such as the Sea of Japan). Crocodile researchers confirm that the specie can swim 15 to 18 miles per hour (6.7 to 8.0 m/s) in short bursts, but when cruising 2/3 mph (0.9 to 1.3 m/s).

The most striking factor behind their disappearing in Sundarbans is that, they are generally very lethargic–a trait which helps them survive months at a time without food–they typically loiter in the water or basks in the sun through most part of the day as they prefer to hunt at night. They are capable of explosive bursts of speed when launching an attack from the water. They usually wait for prey to get close to the water's edge before striking, using their great strength to drag the animal back into the water. Most animals are killed by the great pressure of the jaw, although some animals may be incidentally drowned. It is a powerful reptile, having the strength to drag a fully grown water buffalo into a river, or crush a full-grown bovid's skull between its jaws. Its typical hunting technique is known as the "death roll": it grabs onto the animal and rolls powerfully. This throws any struggling large animal off balance, making it easier to drag it into the water. The "death roll" is also used for tearing apart large animals once they are dead.

Baby saltwater crocodiles may fall prey to monitor lizards, predatory fish, birds, and many other predators. Juveniles may also fall prey to Bengal tigers and leopards in certain parts of their range, although this is rare. Saltwater crocodile is an opportunistic apex predator capable of taking nearly any animal that enters its territory, either in the water or on dry land. They are known to attack humans as well who enter their territory. Juveniles are restricted to smaller animals such as insects, amphibians, crustaceans, small reptiles, and fish. The larger the animal grows, the greater the variety of animals it includes in its diet, although relatively small prey make up an important part of the diet even in adults. Large adult saltwater crocodiles can potentially eat any animals within their range, including monkeys, wild boar, deer; water bird, domestic livestock, and snake, even humans.

The saltwater crocodile has long muzzle; its length is twice its breadth at the base. Its muzzle is longer than fresh water crocodiles. The saltwater crocodile has fewer armor plates on its neck than other crocodilians, and its broad body contrasts with that of most other lean crocodiles, leading to early unverified assumptions that the reptile was an alligator. An adult male saltwater crocodile weighs 600 to 1,000 kilograms (1,300–2,200 lb) and is normally 4.1 to 5.5 metres (13–18 ft) long, although mature males can be 6 metres (20 ft) or more and weigh 1,300 kilograms (2,900 lb) or larger. This species has the greatest sexual dimorphism of any modern crocodilian, with females being much smaller than males. Typical female body length ranges from 2.1 to 3.5 metres (7–11 ft). The largest female on record measured about 4.2 metres (14 ft). The mean weight of the species as a whole is roughly 450 kilograms (1,000 lb). The length of saltwater crocodile varies with controversial extent. There are reports of a 21 ft to 23 ft long crocodiles from Orrisa. However, the specie plays an important role in maintaining the deltaic eco-system as the top consumer. Absence of crocodiles, especially from the Sundarban areas may break the prey-predator relationship and the effect of misbalance may reach to the upward river courses which should be considered a threat to the human society too. Considering the consequences, immediate efforts should be taken-up to encourage the estuarine crocodiles in and around the Sundarban areas by their habitat development and other micro-planning and research findings are urgently required –the experts comment!